Lagging Pipes and Other Insulation

Many people only think of loft insulation when we talk about insulating homes. And there's a lot of that talk about, with rising fuel prices and a growing awareness of ecological issues. But insulating your home shouldn't stop with loft insulation, lagging pipes should be the next port of call at least.

Preventing Freezing Pipes

Heat loss is not the only reason for lagging pipes. Although we think of insulation as a way of preventing heat being lost it is actually more about keeping temperatures stable. So in the case of pipes, lagging can prevent them from freezing in cold weather as well.

When water freezes it expands and can split pipes, often at junctions. It can also damage vales. Of course you don't know about this when they are frozen, all you know is that you have no water or heating. But when the temperatures rise and the frozen water starts to thaw, THAT is when you know about it!

Pipe Lagging Materials

In the olden days pipes were lagged with cloth, wool, old clothing, whatever fibrous material came to hand. But these days it's a lot simpler, with tubes of foam insulation that can be cut to length and taped on. As well as being easier to use the foam insulation is more resistant to flames and fire. This is important when pipes often occupy the same spaces as electrical wiring.

If you are installing pipework you can use complete tubes. These are cut to length and slid on before you put the pipe in place. But as this site is for DIY beginners it's much more likely that you want to insulate pipes that are already in place. Buy insulating foam tubes that are slit along their length so that once you have cut them to length you can ease them over the pipes. Then tape around them with insulating tape or specialist pipe lagging tape.

Close Fitting

One of the tricks with insulation is that small gaps have a disproportionate effect on thermal efficiency. This means it's worth taking care to cover as much of the pipes as possible. If you have access problems, try cutting short lengths, taping them loosely into place then sliding and twisting them down the pipe as far as they will go. Then you can add another piece, slide that down, and so on, until you can't get any further.

At corners and junctions use mitre cuts (at 45 degrees) so that the lagging will meet at the corner. If you cut straight across (at 90 degrees) the corner will be exposed. Where you have taps, cover the body but leave the tap handle free, for obvious reasons!

Loft Tank Insulation

As many of the pipes you are lagging will be in the loft, it's time to pay attention to the insulations around the cold water tank too. It's imperative not to insulate underneath the tank. This will prevent warmth rising from the room below, which will help keep the tank above freezing point.

What you can do is drape loft insulation over the top and sides of the tanks and down to the meet the loft insulation. This will keep the warmth from underneath under the tank for as long as possible. If your tank doesn't have a lid, you need to make one up from a sheet of chipboard or similar material. Do this before you drape the insulation over it.

All-Round Improvement From Lagging Pipes

Once you've finished all of this you may not notice much difference. But as well as lower heating bills and fewer freezing pipes in winter, the heating will warm up faster and hot water will reach basins and sinks slightly faster too. So it's a simple DIY job that's worth doing well.